1. Field of the Invention
Embodiments of the invention relate to a quantum rod light-emitting display device, and more particularly, to a quantum rod light-emitting display device capable of maximizing optical efficiency using a display panel including a quantum rod layer.
2. Discussion of the Related Art
In recent years, highly efficient flat panel displays (FPDs), which may be made ultrathin and lightweight, and which consumes less power, have been required in various fields.
Among these, a liquid crystal display (LCD) has been most widely used as a typical FPD.
As shown in FIG. 1, which is a schematic cross-sectional view of a typical LCD, an LCD 1 may include a liquid crystal (LC) panel 10 including first and second substrates, an alignment film, a color filter layer, and an LC layer; a backlight unit (BLU) 20 including a light source 21, a reflection plate 22, and a plurality of optical films 23; and upper and lower polarizers 31 and 32.
That is, the LCD 1 may need the plurality of optical films 23 and the polarizers 31 and 32 to display a gray level, and the color filter layer to provide colors.
Accordingly, while light emitted by the light source 21 of the BLU 20 is being transmitted through the plurality of optical films 23, the color filter layer, and the polarizer 31, most of the light is lost, thus causing a drop in light transmittance.
Assuming that the amount of light emitted by the light source 21 of the BLU 20 is 100, the final amount of light transmitted through the LCD 1 becomes about 5 to about 10. Thus, the LCD 1 has very low optical transmission efficiency. Accordingly, it is necessary to increase luminance of light emitted by the BLU 20. To increase the luminance of the light emitted by the BLU 20, power consumption should increase, and a large number of components are required during a fabrication process, thereby making it difficult to reduce fabrication cost.
To solve the above-described problems, an organic light emitting diode (OLED) that does not require additional polarizers, color filter layers, and optical films has been proposed.
The OLED is an element configured to emit light during recombination of electron-hole pairs formed by injecting charges into an organic emission layer (EML) formed between a cathode serving as an electron injection electrode and an anode serving as a hole injection electrode.
The OLED may be formed on a flexible substrate, such as a plastic substrate, have a good color sense due to a self-emission function, be driven at a lower voltage of about 10V or lower, and consume less power than an LCD.
However, in the OLED, organic emission materials forming the organic EML have greatly different lifetimes according to the color of light emitted by each of the organic emission materials. In particular, a blue emission material has a relatively short lifetime, which is shorter than the lifespan of a typical display device.
Accordingly, it is still necessary to develop an FPD that has high optical efficiency, as long a lifespan as an LCD, and may be driven with low power.